Thermoregulator



Oct. 12, 1937. L. D. GOODHIIJE THERMOREGULATOR Filed Jan. 29, 1937 Patented Oct. 12, 1937 UNITED STATES PATENT OFFICE THERMOREGULATOR Lyle n. Goodhue, Berwyn, Md.; dedicated to the free use of the People of the United States Application January 29, 1937, Serial No. 123,031 i'oiaim. (Cl. 200-141) (Granted under the act of March 3, 1883, as

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented, may be manufactured and used'by or forthe Government for governmental purposes without the payment to me of any royalty thereon.

I hereby dedicate the invention herein .described to the free use of the Public in the territory of the United States of America. to take effect 10 upon the granting of a patent to me.

My invention is a new and novel thermoregulator of the type that depends on the change in vapor pressure of a volatile liquid with change in temperature. Although this type of regulator 15 has been known for a long time no one has combined certain physical principles in such a way as I have to produce a regulator that is extremely sensitive to slight changes in temperature yet which can be used to carry and make and break 20 currents up to 15 amperes at 110 volts. My regulator is constructed so that the electrical circuit is broken by a rise in temperature, and since it has a very high current carrying capacity, it can be used directly in series with an electrical heat-' ing ,unit without a relay. This new regulator is suitable for controlling the temperature of rooms, railroad cars, air chambers, water tanks, etc., where electrical heating units or other electrical devices are used alone, or in combination 30 with the control of heat from some other source as, for example, the regulation 01' an oil burner. My regulator has many advantages. It is easily constructed from a good grade of glass tubing. It does not require sealed in electrical 35 leads and it is made very sensitive by employing the principle of. the differential manometer. No condenser is needed to protect the contact points from corrosion since they are actually the ends of two columns of mercury in an 'atmosphereof 40 hydrogen. No disturbing noises are made at any time during operation. 1

The details of the construction 01' the apparatus are shown in the accompanying drawing, in

. which Fig. 1 is a front view of the entire device 45 and Fig. 2 is a side view thereof. The glass tubes I and 2 are about 10 mm. in diameter and 16 to 20 cm. long. The tubes 3 and I have a much smaller together at 5 to form an inverted V with the tube 6. The. small trap 'l is inserted to condense and return any mercury vaporized by the making and breaking oi the electrical circuit. The tube 6 from the trap l to within aiew cm. of the bulb 8 is preferably made from 2 mm. thick-walled capil- 55 lary tubing. The bulbs 8 and 8 are inserted to diameter, 3 to mm. Tubes 3 and 4 are joined amended April 30, 1928; 370 O. G. 757) protect the adjustment of the regulator when exposed to extreme changes in temperature. The bulb ll contains the volatile liquid it the vapor of the liquid, and air or some inert gas. The shaded portions indicate the parts of the regula- 5 tor filled with mercury. Nos. 12 and I3 indicate the electrical leads which may be of any metal that has a low resistance and is not amalgamated by mercury. Tube No. 6 from the point 5 through the trap l and around to the mercury in the bulb 8, contains pure hydrogen or some other gas that will noireact with mercury.

My regulator is filled in the following manner: The glass is carefully cleaned and dried to remove all moisture. Dry hydrogen gas is passed 15 into the bulb I I, the tip then being open. until all air is swept out. A small quantity of mercury is poured into tubes 1 and 2 which forms a trap in the lower bend of tubes 3 and 4. The fiow of hydrogen is now interrupted at H and a quantity of mercury is introduced into H from where it runs down into the bend of tube 6 below bulbs 8 and 9. This procedure traps a quantity of hydrogen in tube 6 and a part of tubes 3 and 4. More mercury is added to tubes l and 2 and again to II. Some of the hydrogen in 6 is now removed by applying suction to II until the'amount of hydrogen remaining in tube 6 will allow the mercury in the tubes to stand nearly at the same height. This process is repeated until the desired amount of mercury has been added as shown in the figure, The volatile liquid, ether, pentane, carbontetrachloride, or other liquid is introduced into I l until the bulb is half filled. The tip of II should be sealed when the apparatus is near the temperature at which it is to be used.

The regulator may now be adjusted over a range of approximately 10 degrees by adding to,

Dr removing mercury from, the tubes I and 2. The electrical circuit is broken at a higher temperature if mercury is added. A fine adjustment may be provided by fitting a glass plunger through a loose fitting stopper in tube l. Displaclng the mercury with glass has the same eii'ect as adding more mercury. This plunger is not necessary 4 for the perfect operation of the regulator.

In further explanation of the operation of my regulator, I wish to point out that the change in vapor pressure of the volatile liquid moves the mercury in tube 6. This in turn compresses the hydrogen in tube 6 which forces the mercury column to break at 5 and thereby break the electrical circuit. Upon'cooling the reverse action takes place and the circuit is closed. A range 01' 0.05 C. to 0.1 C. is sufflcient to make and break the circuit. By making tubes 8 and 5 almost horizontal at the joint 5 and their diameters small in comparison to tubes i and 2, a diflerential manometer is formed. In other words, a slight change in pressure in the tube 8 causes a large movement of the mercury columns at 5 and a comparatively small movement in tubes I and 2. This is an important feature of my regulator. Also this construction causes the mercury to make contact quickly and to break quickly, thus reducing the arcing to a minimum. By combining all these important physical principles I have produced this new thermoregulator.

My regulator has been tested by using it to maintain the temperature of a room at 27 C. It was used in series with a 1350 watt heater directly on 110 volts. No other equipment was necessary. The control was excellent during a test period or one month. c

Having made a full disclosure of my invmtion, I claim: v

A 'thermoregulator comprising two vertical glass tubes, two U tubes of smaller diameter than the first mentioned tubes, one arm of each U tube being fused to the lower end of one of the vertical tubes, the other ends of the U tubes being joined in the form of a V, an inverted U tube one arm of which is fused to the u tubes at their junction point and having a trap just above said Junction, a third U tube formed integral with the other arm of said inverted U tube, each armof such'third U tube having a bulb, and a closed the mercury columns, a body of volatile liquid,

and inert gas in said closed reservoir and electric leads contacting the mercury in thefirst two mentioned U tubes.

LYLE D. DHUE. 

